This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Introduction: Social housing for captive nonhuman primates has been shown to reduce the frequency of abnormal behavior and to increase species-typical behavior. In addition, previous research at the Tulane National Primate Research Center using male rhesus macaques implanted with telemetry devices has shown that physiological parameters correspond to the behavioral parameters of successful social introductions. The purpose of this ongoing study is to examine the long-term effects of social introduction by measuring, via physiological and behavioral means, the potential of social housing to act as a buffer to stressful events. Methods: The monkeys were first implanted with telemetry devices. They were initially housed singly, and during this phase, both behavioral and physiological data were collected during 30-minute focal animal samples. During this time, potentially stressful events that occurred as part of the monkeys'daily routine were documented with physiological and behavioral parameters. The monkeys were then paired, and once they were in settled social pairs, the data collection as described above was repeated. Twelve M. mulatta were enrolled on the study. Behavioral and physiological data have been collected on all subjects. Results/Discussion: When visually exposed to the restraint and anesthesia of another monkey in the room, monkeys that are pair housed show statistically significant reductions in rates of abnormal behavior. No statistically significant differences were seen when dominant and subordinate individuals were compared. The results of this study indicate that social buffering during stressful events can be considered an additional benefit to the well-being of socially-housed laboratory nonhuman primates. This is important in research because both physiological and behavioral parameters can affect the outcome of data during a study.